1. Field of the Invention
The present invention relates to a product sorter that may be used as, for example, a selection apparatus for sorting or diverting rejected products out of the normal course of transport of acceptable products. When the products are judged unacceptable at the preceding inspection station where a weighing machine or an inspection machine such as, for example, a metal detector or an X-ray inspecting machine is installed, on the account that they have failed to satisfy the required weight or are found to be either out of allowable weight range or including metal foreign matters.
2. Description of the Prior Art
The product sorter of this kind is known which includes a support frame and a transport conveyor supported by the support frame and including a transport belt trained around and between a drive roller (a drive rotatory body) and a driven roller (a driven rotatory body). The transport conveyor is pivotable together with the support frame about a pivot axis coaxial with the drive roller to divert the rejected products out of the normal course of transportation where the acceptable products are transported. In this type of the product sorter, since the transport conveyor, particularly the transport belt thereof is susceptible to contamination brought about by the products being transported, the transport belt is routinely removed out of the apparatus for detergent or cleansing. To facilitate removal of the transport conveyor belt, the Japanese Laid-open Patent Publication No. 2000-159336, for example, discloses the transport conveyor so designed and so configured as to be bendable or foldable. However, it has been found that when the transport conveyor is folded, screws and stoppers have to be removed, resulting in complicated folding work.
Also, for the diverting operation, left and right side plates of the support bracket are designed to extend downwardly and a pivot shaft is journalled between the respective extensions of the framework side plates in a relation parallel to the pivot axis while an actuator in the form of a pneumatically operated cylinder for activating a diverting operation is coupled with an axially intermediate portion of the pivot shaft. As such, the framework side plate extensions and the pivot shaft having a substantial length are required, resulting in increase in size of the sorter as a whole. Moreover, since the actuator is positioned immediately beneath the transport conveyor, foreign matter such as dirt and/or spills from the products being transported may adhere to the actuator and the actuator may eventually fail to operate properly and/or may be contaminated undesirably.
In view of the foregoing, the present invention is intended to provide an improved product sorter of a type wherein the transport belt can easily be removed from the transport conveyor of the product sorter for detergent or cleansing.
In order to accomplish the foregoing object of the present invention, the product sorter according to the present invention is designed to divert the products being then forwardly transported to a plurality of positions by performing an up and down pivotal movement about a pivot axis. For this purpose, the product sorter according to the present invention includes a transport conveyor including a conveyor frame, a rotatory drive body mounted on one of opposite ends of the conveyor frame, a rotatory driven body mounted on the other of the opposite ends of the conveyor frame, and an endless transport belt trained around and between the rotatory drive and driven bodies, while the transport conveyor is capable of being bent when mounted on or removed form a support framework; a drive source for driving the rotatory drive body to drive the transport belt; an actuator for pivoting the support framework up and down; and a stopper member for inhibiting the conveyor frame from being bent upwardly. In this product sorter, an axis of pivot of the conveyor frame is positioned at a location displaced downwardly from an imaginary straight line connecting between respective axes of rotation of the rotatory drive and driven bodies, respectively, when the conveyor frame is not bent and the conveyor frame is capable of being bent downwardly.
According to the present invention, since by bending the transport conveyor the distance between the rotatory drive and driven bodies can be shortened, the transport belt can easily be removed from the rotatory drive and driven bodies. It is to be noted that the axis of pivot of the conveyor frame is positioned at a location displaced downwardly from an imaginary straight line connecting between respective axes of rotation of the rotatory drive and driven bodies, respectively, when the conveyor frame is not bent and the conveyor frame is capable of being bent downwardly. In addition, the stopper member for preventing the conveyor frame from being bent upwardly is employed. Accordingly, when the conveyor frame is not bent, that is, held in a straightened position, the conveyor frame tends to bend upwardly about the axis of pivot by the effect of a resilient restoring force of the transport belt. Since this tendency of the conveyor frame to bend upwardly can be inhibited by the stopper member, the conveyor frame can advantageously supported in the straightened position stably with the products assuredly transported thereby. When, starting from this condition the transport conveyor is to be bent, a manual lift of a portion of the transport conveyor adjacent the axis of pivot thereof results in the transport conveyor being pivoted about the axis of pivot and, thus, neither screws nor pins need be turned, thereby facilitating a bending work extremely easy.
The bendable conveyor frame may include, for example, a frame body supporting the rotatory drive body and forming a major portion of the conveyor frame, and a frame segment forming a part of the conveyor frame and supporting the rotatory driven body and supported by the frame body for pivotal movement up and down about a pivot axis 25a extending leftwards and rightwards. This structural feature is effective to provide the bendable conveyor frame of the structure in which the frame body and the frame segment are merely connected together by means of the axis of pivot. Also, since the rotatory drive body, which has hitherto been more complicated in shape than the rotatory driven body because of the use of a mechanism for coupling it with the drive source can be supported by the relatively large frame body, it is possible to design this support means without being constricted by the limited space.
As a method of providing the stopper member, for example, an upper region of the conveyor frame may include ceiling members facing an inside surface of an upper run of the transport belt, so that when the frame segment is bent upwardly, the frame segment can be brought into abutment with a forward end of the ceiling member of the frame body to thereby inhibit the frame segment from being bent upwardly.
In a preferred embodiment of the present invention, the support framework may include a first support unit for supporting one end of the rotatory drive body, a second support unit for supporting the other end of the rotatory drive body and a pair of third support units for supporting opposite ends of the rotatory driven body. The first support unit is provided in correspondence with one end of the rotatory drive body for transmitting a drive force from the drive source when the transport conveyor is mounted on the support framework and also for supporting one end of the rotatory drive body while inhibiting motion of such one end of the rotatory drive body in a direction forwardly and rearwardly and also in a direction upwardly and downwardly. The second support unit is provided in correspondence with the other end of the rotatory drive body and opening upwardly for supporting such other end of the rotatory drive body while inhibiting motion of such other end of the rotatory drive body in a direction forwardly and rearwardly and also in a direction downwardly when the transport conveyor is mounted on the support framework. The third support units are provided in correspondence with the opposite ends of the rotatory driven body and opening in a direction towards the rotatory drive body, and support the opposite ends of the rotatory driven body while inhibiting motion of the opposite ends of the rotatory driven body in a direction upwardly and downwardly when the transport conveyor is mounted on the support framework.
According to the foregoing structure, since the third support unit opens towards the rotatory drive body, bending of the transport conveyor on the support framework while supporting the transport conveyor at the first and second support units allows the opposite ends of the rotatory driven body of the transport conveyor to be moved from the third support unit towards the rotatory drive body to thereby separate from the third support unit. When while in this condition the opposite ends of the rotatory drive body of the transport conveyor are removed from the first and second support units, the transport conveyor can easily be removed from the support framework. It is to be noted while the transport conveyor is supported on the support framework, the position of the transport conveyor in the forward and rearward direction can be regulated by the first and second support units of the support framework while the position thereof in the up and down direction can be regulated by the first and third support units, and, therefore, the transport conveyor can advantageously stably be supported by the support framework.
In another preferred embodiment of the present invention, the support framework may include a first side plate positioned on one side of any of the rotatory drive and driven bodies having the first support unit and one of the third support units, and a second side plate positioned on the other side of any of the rotatory drive and driven bodies having the second support unit and the other of the third support units and connected with the actuator. According to this structure, since the actuator and the drive source are arranged on respective sides of the rotatory drive body, the apparatus as a whole can be well balanced.
Connection between the rotatory drive body and the drive source by the first support unit may take any form. For example, a rotatory connecting shaft and a coupling may be employed for this purpose. In such case, the rotary connecting shaft is to be disposed coaxially with the rotatory drive body at a location outside one end of the rotatory drive body and arranged to be driven by the drive source, and the coupling is to be used for releaseably connecting the rotary connecting shaft and one end of the rotatory drive body for axial movement, but non-rotatably relative to each other. In this case, the first support unit includes a bushing for axially separably retaining the coupling. With this structural feature, by causing the end of the rotatory drive body to be mounted or detached axially relative to the bushing of the first support unit, the rotatory drive body can easily be connected or separated relative to the drive source through the coupling.
In a further preferred embodiment of the present invention, the first and second support units of the support framework may cooperate with each other to allow the transport conveyor to be supported by the support framework with the axis of rotation of the support framework aligned with the axis of rotation of the rotatory drive body, in which case the actuator is connected with the rotary shaft fitted to the second support unit and having the axis of rotation. This design is particularly advantageous in that neither a relatively long shaft for connecting the actuator with the support framework nor any extension of the conveyor frame for mounting the long shaft is needed, resulting in the structure to be simple and compact in size. Also, since the point of action of the actuator coincides with the axis of pivot of the support frame, movable parts including the rotary shaft can be centered at a single location. Therefore, when the protective covering is fitted over the actuator, a sealing between the protective covering and movable member, that is, the rotary shaft is required at only one location, and, accordingly, an assured waterproofing can be obtained.
In such further preferred embodiment of the present invention, the product sorter may also include an end member supported by the conveyor frame for rotatably supporting the other end of the rotatory drive body, and the second support unit includes a first receiving groove opening upwardly for receiving an engagement stud of the end member from above to thereby inhibit the engagement stud from being shifted in a direction forwardly and rearwardly and also in a direction downwardly. According to this structural feature, by mounting the end member in the first receiving groove from above or pulling it upwardly from the first receiving groove, the other end of the rotatory drive body can easily be mounted on or removed from the conveyor frame.
The third support unit for allowing the opposite ends of the rotatory driven body to be supported by the support framework may include, for example, a second receiving groove opening towards the rotatory drive body for supporting an engagement projection, provided in the conveyor frame, while inhibiting the engagement projection from being shifted in a direction upwardly and downwardly, and the support framework may be formed with a guide surface inclined upwardly towards the rotatory drive body from the second receiving groove for guiding the engagement projection in a direction allowing it to be inserted into or separated from the second receiving groove when the transport conveyor is mounted on or removed from the support framework, respectively. With this structure, the engagement projection of the support framework can be smoothly inserted into or separated from the second receiving groove by the utilization of the guide surface.
Preferably, the axis of rotation of the support framework may be set at one end positioned upstream and the actuator may correspondingly be arranged laterally of the transport conveyor or upstream of the transport conveyor. This is particularly effective in that any possible deposition of dusts on the drive source and/or the actuator during transport of products can be advantageously suppressed and in that the dusts falling below the transport conveyor can easily be cleaned.